With the continuous development of the field of mobile communications, abundant mobile network resources, for example, third generation (3G), wireless fidelity (WiFi), and Worldwide Interoperability for Microwave Access (WiMAX), exist around us. Because a terminal can use only one type of network at a time, when the terminal hands over from one type of network to another type of network, a connection to a network that is currently used is interrupted, which affects use experience. Therefore, the user urgently requires a network handover method that may perform a seamless handover.
Referring to FIG. 1, which shows a schematic structural diagram of a network provided by the prior art of the present invention. Using that a terminal hands over from a first network that is currently used to a second network as an example, an existing network handover method is as follows: (1) The terminal, when detecting that the terminal enters an overlapping coverage area of a base station of the first network and a base station of the second network, establishes a data-layer connection to the base station of the second network, and sends a handover request signal to the base station of the second network; (2) the base station of the first network, the base station of the second network, and a gateway perform a handover procedure according to the Media Independent Handover protocol, so that the gateway may provide a service for the terminal using the base station of the second network; (3) the base station of the first network and the base station of the second network perform frame synchronization using the gateway; (4) the base station of the second network returns a handover completion indication to the terminal, so that the terminal receives a service using the base station of the second network; and (5) the base station of the first network and the gateway retain a connection to the first network, so that the terminal may be handed over from the second network back to the first network later.
During implementation of the present invention, the inventor finds that the prior art has at least the following problems:
In the existing network handover method, after a base station of a first network, a base station of a second network, and a gateway perform a handover procedure according to the Media Independent Handover protocol, the base station of the first network and the base station of the second network must perform frame synchronization using the gateway; however, a process of the frame synchronization needs to take a long period of time, which usually affects normal use by a user and increases complexity of a network handover process.